1. Field
The present invention relates to fuel injection devices of saddle-ride type vehicles and particularly to a fuel injection device of a saddle-ride type vehicle capable of rapidly carrying out acceleration correction according to throttle operation.
2. Description of the Related Art
A fuel injection device of an internal combustion engine that decides the fuel injection amount based on the engine rotational speed and the throttle opening has been known in the past.
Patent Document 1 (Japanese Patent No. 4046718) discloses the following fuel injection device of the internal combustion engine. The fuel injection device detects the throttle opening at interrupt timing of a crank pulse output from a crank pulsar rotor that detects the rotation state of the crankshaft, and performs sequential injection with a basic injection amount in accordance with an injection amount map defined in advance. In addition, if the amount of time change of the throttle opening is equal to larger than a predetermined value, the fuel injection device determines that there is a request for acceleration and performs non-sequential injection with an acceleration correction amount in addition to the basic injection amount.
In the case of cornering driving on a saddle-ride type vehicle typified by the two-wheeled motor vehicle, the following driving form is taken. At the stage prior to corner entry, the vehicle body is inclined (banked) with reduction of the engine torque by brake operation, shift-down operation, and close operation of the throttle opening, to perform turn driving. Then, at the leave from the corner, the vehicle body posture is changed from the banked state to the upright state with increase in the engine torque by open operation of the throttle opening, and subsequently the vehicle speed is accelerated with shift-up operation. That is, there is a characteristic that the posture change of the vehicle body is larger than the four-wheeled vehicle. Therefore, rapid response to the throttle operation is desired.
Furthermore, regarding the two-wheeled motor vehicle, there are many demands to enjoy an acceleration feel that cannot be offered by the four-wheeled vehicle in, for example a touring ride, and rapid response to throttle open operation is desired.
However, in the case of abandoning the cam pulse rotor that detects the rotation state of the camshaft to reduce the number of parts, a stroke determination of the engine needs to be made by the crank pulsar rotor. Therefore, in the crank pulsar rotor, a toothless part of a predetermined length is formed besides protrusions disposed at substantially equal intervals. In this case, in a configuration that detects the throttle opening based on crank pulse interrupt and calculates the injection amount like in Patent Document 1, there is a problem that throttle operation cannot be detected during the passage of the toothless part and it is difficult to obtain rapid response in this transient region.